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Knot · Joining two lines

The surgeon's knot

Join two nylon lines in thirty seconds, at night, in the rain. The universal fix.

Technical sheet
Indicative strength
  • 65 % of line strength, triple version, nylon to fluorocarbon
  • 80 % of line strength, quadruple version, braid to fluorocarbon
Source: Field & Stream, “Tie the strongest fishing knots”, John Merwin’s tensile tests, updated in 2026. Indicative values: they vary with the line and the care taken when tightening.
DifficultyEasy
UseJoining two lines
Compatible linesnylon, fluorocarbon

See it in 3D, step by step

The surgeon's knot
The surgeon's knot 1 lay the two lines side by side, in opposite directions. 2 form a loop with the two lines held together. 3 pass both ends through it together a first time. 4 then a second time through the same loop. 5 wet, pull on all four strands.

Step by step

  1. Lay the two lines side by side, in opposite directions
  2. Form a loop with both lines held together
  3. Pass both ends through it together a first time
  4. Then a second time through the same loop
  5. Moisten, pull on all four strands
The test before fishing

Pull on all four strands, then on the two main lines: the knot must stay compact, with no loose ear.

The version shown here is the double (two passes); the published tests cover three and four passes.

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Rigs that use it

Which fish

All knots · The technical notebook